In her first comment on the controversy, Ms Fitzgerald said: “The issues in question are likely to lead to court challenges.”

Ms Fitzgerald said emergency amending legislation could be introduced, possibly within days.

However, she said advice on the matter was still awaited from Attorney General Maire Whelan.

Senior legal figures say they expect a raft of challenges in the coming days after Mr Justice Michael Moriarty of the High Court issued a ruling striking down Section 99 of the Criminal Justice Act 2006, finding it to be unconstitutional.

This is the section of law governing the power of the courts to activate sentences which were originally suspended.

Until yesterday someone found guilty of reoffending while serving a suspended term could be swiftly committed to prison under Section 99 to serve out the suspended portion of their initial sentence.

Mr Justice Moriarty found the law was unfair as it denied people the right to challenge their second conviction before being committed to prison in relation to their first.

Two sentence activation applications were delayed yesterday amid the uncertainty created by the ruling.

In a statement, Ms Fitzgerald said the matter was under “urgent examination” by the Attorney General.

“The Government will take all necessary action open to it to address the issues arising from Judge Moriarty’s judgment,” she said.

“While legislation cannot retrospectively affect criminal cases before the courts, if, in the light of the consultations with the Attorney General, it is concluded that amending legislation is necessary, this can be introduced in the Dáil very quickly – if necessary within days.”

Ms Fitzgerald sought to play down fears there could be a mass exodus of prisoners from jails.

She said she believed convicts who had not previously raised concerns in relation to Section 99 would be unable to successfully apply for their release.

“There are no grounds for believing that persons generally who had not raised this issue in the course of proceedings which have been concluded will now be able to benefit from the finding of the High Court,” she said.

Mr Justice Moriarty’s ruling is the first major legislative crisis to emerge since the election more than seven weeks ago.

The ruling came as a result of separate cases brought by six young men, convicted of offences ranging from public order to driving without insurance, attempted robbery and violent disorder.

As a result of the ruling criminals already behind bars could seek to be released.

As has already been seen, cases before the courts are also likely to be delayed.

The ruling has also created uncertainty over cases where a judge might be expected to hand down a suspended sentence.

Within hours of the ruling, two cases at Dublin Circuit Criminal Court stalled. The judge said she was only in a position to "request" that the accused attend the next sitting of the court.

Suspended sentences are used regularly by judges to give offenders an incentive to stay on the right side of the law.

If the person commits a separate offence while serving a suspended sentence, they are automatically returned to jail.

However, Mr Justice Moriarty declared key parts of Section 99 unconstitutional, on grounds including that it allowed for significantly different treatment of persons as far as their rights of appeal are concerned.

A senior criminal lawyer told independent.ie: "After this ruling, any decent lawyer will be down the courts seeking to test whether they can have their clients freed if they were dealt with under Section 99."

Problems with the application of Section 99 have been well flagged in the past by the judiciary.

Mr Justice Moriarty said the section was in need of "urgent and comprehensive review".

He said it was drafted and enacted by persons "quite unacquainted of the actual practices of the courts".

Taoiseach Enda Kenny told the Dáil today that legislation can be brought forward “despite the fact we do not have the endorsement of a new Government”.

He said the laws governing suspended sentences had a positive impact when it was introduced in 2006.

“Prior to the introduction of the legislation, suspended sentences were handed down but were seldom reactivated and did not, therefore, act as a deterrent to repeat offenders,” he said.

“While indications are that this judgment will potentially have an impact on a limited number of cases where a suspended sentence was recently activated, it is important that the difficulties identified by the courts are addressed.

“I am confident that this can be done. I have spoken to the Minister for Justice and Equality and the Attorney General. The Department of Justice and Equality is in consultation this morning. If necessary, that matter can be dealt with effectively here in a number of days,” Mr Kenny said.